microbe susceptibly expanded in gut of human with disease participates in gout Escherichia coli Escherichia coli EPEC 32/73 Escherichia coli EPEC 32/73 Escherichia coli str. EPEC 32/73 Escherichia coli strain EPEC 32/73 expansion of Escherichia coli EPEC 32/73 in gout human gut